Screw conveyors have long been known in the material handling art. Generally, such conveyors have the capability of transporting a wide variety of materials, usually between predetermined starting and ending points, with the ending point frequently located higher than the starting point. Special considerations must be given to conveyor facilities that are used in a sanitary environment. Examples are found in conveyor systems used in the food industry for preparation and handling of food products, and in the manufacture of pharmaceutical products and other products which are eventually consumed or come into contact with human end users. These conveyor systems must typically meet stringent sanitary requirements, typically requiring daily or other frequent take down and cleaning. At times, successive products carried by a conveyor even if sanitary, may be incompatible with one another or otherwise produce undesired results if residue from one product is allowed to come into contact with another product carried by the same conveyor system.
Portable conveyors, especially those used in a sanitary environment present additional challenges to be overcome. For example, portable conveyors may be desired for temporary or intermittent use for a given job, and upon relocation to a different work site may be used to handle a different material. For example, a portable conveyor system may be desired for use in the food preparation industry where large quantities suitable for industrial manufacture are mixed together for different batches of the same or similar products, or for different, unrelated products. Not only must the conveyor equipment be readily maintainable for sanitation purposes, the equipment must also be as free as possible from contamination caused by inadvertent contact with the surrounding environment. For these and other reasons, it is often desirable to provide a conveyor system that is self-contained, thereby reducing the need for external power sources, drive equipment and the like which may introduce contamination and other problems that are unique to operation in a sanitary environment.